Sequelize Transaction Bulk Update followed by Bulk Create

Question

I am working with Sequelize transaction and would like to know how to do a bulk update before sequentially doing a bulk create.

My current code is something like this:

return sequelize.transaction(function(t){
  return sequelize.Promise.each(arrToUpdate, function(itemToUpdate){
    model.update(itemToUpdate, { transaction: t })
  }); 
  //How to do a sequential bulk create after the bulk update is successful in sequelize
  //transaction?
  //Bulk Create code would be return model.bulkCreate(itemsArray, { transaction: t })
});

Solution

I believe you're just after promise chaining with then? The first line should return a promise - so just call then on the result:

return sequelize.transaction(function(t){
  return sequelize.Promise.each(arrToUpdate, function(itemToUpdate){
    model.update(itemToUpdate, { transaction: t })
  }).then((updateResult) => {
    return model.bulkCreate(itemsArray, { transaction: t })
  }, (err) => {
    // if update throws an error, handle it here.
  }); 
});

Note: now your function will return a promise, so whatever calls your function will have to use then to get a handle on the result.

Comments

[Chua Bing Quan]

Thank you, I did not think of that! Was too caught up on the return model.update() inside the loop.